These comments make sense to me. I hiked the PCT using a Mariposa Plus, and it worked, but the weight I loaded it with through the Sierras put some stress on it and it was pretty worn by the time I finished. I used another somewhat used Mariposa Plus on the AT, and got about half-way through before my hiking buddy convinced me it was time to replace it.

I replaced it with a ULA Circuit that is still my go-to pack. I think I might be approaching 5000 miles that that pack now, and while it's worn/wearing in various places now, it's held up very well IMO, relative to amount of use, and the relative light weight and mix of pack features. My hiking friend had put at least 3000 miles on his ULA Catalyst when he replaced it.

ULA packs are a good choice for long distance hiking. If you're not putting quite so many miles on a pack, however, the lighter packs can be a great choice. I'll bring one of my fairly-beat-up Mariposa packs with me to Spain later this year I think --- I won't need to load it up that much there.